FIG. 1 illustrates a known reference model for a radio access network (RAN). A base station controller/radio network controller (BSC/RNC) 10 is coupled to a plurality of wireless base station 12, 14, 16, 18 via a radio access network 20. The radio access network can be modeled as a radio network layer (RNL) 22 and a transport network layer 24 and three planes intersecting those layers, a radio network control plane 26, a transport network control plane 28 and a user plane 30. The network may be leased from a service provider (SP) or owned by the wireless service operator.
In operation, the transport network layer (TNL) receives a request from the RNL to establish a bi-directional transport bearer for datagram traffic. The request includes the end system address and transport bearer association received from the peer. It also includes the quality of service and resources required from the transport network. In summary it shall:                Provide unique connection identifiers such that individual flows can be uniquely addressed for both user plane as well as control plane (eg VPI, VCI, CID in AAL2/ATM);        Provide in-sequence delivery of PDUs to upper layers;        Support sending coordinated dedicated channels (DCHs) multiplexed onto the same transport bearer (i.e., frame multiplexing, e.g. AAL2/ATM);        Provide proper mappings of required RNL bearer channels QoS to TNL resources (eg AALx in ATM); Provide transport signalling protocol used to setup and tear down transport bearers (eg ALCAP in 3GPP r3);        Provide segmentation and re-assembly mechanism in order to fit to the maximum PDU size (i.e., R3 ATM AAL2 SSSAR layer function);        
FIG. 2 illustrates a known RAN network system model. The RAN network system model includes the wireless base station controller 10, the wireless base station 12 and an intervening transport network (TRAN) 40. The TRAN 40 includes points of attachment (PoA) 42 and 44 and intranetwork switching collectively represented by function block 46. For the system model of FIG. 2 the current network connectivity model is a peering model. For the peering model: User traffic is “peered” with Service Provider's network at point of attachment (PoA) via rudimentary/sophisticated User Network Interface (UNI). In this model, user quality of service (QoS) requirements are snooped by the SP or signaled from user to the SP (via the UNI interface) in order to satisfy required QoS guarantees.
Consequently wireless datagrams need to be processed by both wireless end points and SP TRAN equipment. This means all sub-systems need to have common understanding of: QoS information, Signaling capabilities and Flow segregation ID across PoA. The known RNL peering connectivity model imposes upon the TNL the need to also implement a peering connection-oriented model; current implementations of datagram addressing are peering-like, coupling RNL 22 (DCH-ID, etc) and TNL 24 (AAL2 CID, etc) identifiers.
Emerging connectionless protocols, such as IP are being proposed as the new TNL transport mechanism and will have to meet connection-oriented requirements
In order to use connectionless IP, development of mechanisms to offer connection-oriented capabilities to wireless TNL layer needs to take place.